Harlequin Ladybird invasion – nature or nurture?

Harlequin Ladybird_20090723_800

Harlequin Ladybird (click to enlarge)

Here is a picture and a brief video clip of a Harlequin Ladybird. They exhibit a wide range of coloration and spot patterns, so if you want to see more photos, visit the Ladybird-Survey.org website and check out their excellent photo ID guides.

Yet another press release emerged about the Harlequin Ladybird colonising the UK, saying that 2009 is bound to favour the invader. A hot summer should extend their breeding season and enable them to thrive.

This big and tough Asian ladybird was employed in the USA as a ‘biological pest control’ against aphids – but as you might expect, things didn’t go exactly as planned. Harlequin Ladybirds do eat aphids, but they also eat a whole host of other creatures, including butterfly eggs, caterpillars and OTHER ladybirds. Back in 2004 the Harlequin Ladybird was first recorded in the UK, and it caused quite a fuss.

So what?

There are news stories about the invasion every year. In 2008 scientists from the Centre for Ecology and Hydrology, Cambridge University and Anglia Ruskin University described it as ‘the most invasive ladybird on Earth’. I suspect that this year’s speculation might be a PR stunt, because the news is futile… I mean, what are we supposed to do? What action are we supposed to take? Should we write to Gordon Brown?

To get your attention the media always feel the need to make it ultra-interesting and a story about a spotty beetle is not the most enthralling topic to most people. So to make sure you take notice the newsreaders and reporters usually hint that the  ‘crisis’ will come sooner rather than later.

As part of the panic-raising, some articles even focus on the potential damage that we might see from ‘attacks on soft fruit’ which could leave… unsightly marks. Alongside their appetite for native ladybirds, lacewings and butterfly eggs, who could love a Harlequin?

Worst of all, they might bite people. Imagine! It might get sore. OMG! Occasionally, they say. When peckish and there’s nothing in the bush. Yeh, but anyway, just imagine!

Nature or Nurture?

Did the Harlequin Ladybird get here with human help, or did they arrive on the wing? Does it matter? What if the Seven-spot Ladybird, whose range includes massive areas of the world, originated in Asia too? Would you love it less? When did it invade the isles known as British and when did it qualify as ‘native’?

If new species are a bad thing, and will upset the ‘balance’ people imagine exists in Nature, then a much greater wave –  let’s call it a TSUNAMI of invaders – might be worth considering. Climate change will bring flying insects our way at a faster rate than modern naturalists have ever known. Higher temperatures, new wind currents, less frost and altered migration instincts could all add up to more new insects and spiders (SPIDERS!) and orchids (ooh nice) coming over here. From over there.

The truth is, the influence of these new ladybirds in the British context is unknown. Perhaps the harlequin will strike a big blow this year, perhaps not, but don’t we need evidence?

Be part of the learning process

Knowing where harlequins live and how fast they spread across the UK will help scientists to gain an understanding of what impact these colourful killers begin to make on the native British insect community.  For instance, surveys of other ladybirds could be carried out in areas where the Harlequin is present and absent. Eventually the data might show how our native ladybirds are being affected where Harlequins move in.

The Natural History Museum set up a campaign, the Harlequin Ladybird Survey, in 2005. They would welcome your sightings.

Jason Ball @ Natureheads.com

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3 Responses to “Harlequin Ladybird invasion – nature or nurture?”

  1. The aliens take many forms « the Natureheads blog Says:

    […] was black with red spots, but the Harlequin Ladybird comes in many […]

  2. Annabel Says:

    My flat is infested with Ladybirds can you advise me how to get rid of these please. They are in my food cupboards on the windows in my sitting room and kitchen. When I have killed a few they smell awful.

    Many thanks

  3. natureheads Says:

    Hi Annabel,
    It it were me, the ladybirds could stay there all winter, and I’d be happy to have them as guests..!

    However, I can understand you feeling as if the house has been invaded And of course they’ll wake up sometimes when it’s warm! Tell me, do you keep the house very warm? If not, then I’d try warming the house on a very sunny day, to wake them from hibernation. When they are all flying at the windows, let them out… that could work.

    Or try to gently collect the ladybirds into cardboard boxes. Use a small brush – like an artist’s brush, or a pastry brush. Put the ladybirds safely in a garage, or somewhere dry – place the boxes on a shelf (labelled!). If you don’t have a dry space where you can keep them, offer them to somebody who does. Gardeners should be very grateful to have their own supply of aphid-eaters ready for spring.

    Remember to let the ladybirds out when the weather warms up!

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